Some chemical vapor deposition (CVD) processing chambers utilize a dielectric (e.g., aluminum oxide) gas feedthrough to flow process gases from a grounded gas manifold to a mixer that is electrically coupled to an RF power source. The inventors have observed that when a metal-organic precursor gas is flowed through conduits of such a gas feedthrough, the precursor gas is thermally decomposed on the inner surfaces of the conduits. Due to weak adhesion of the decomposed material on the inner surfaces, the quality of a deposited film on a substrate disposed in the processing chamber is negatively affected.
Therefore, the inventors have provided embodiments of an improved gas feedthrough assembly.